First off, make sure it's a good product.
If it applies directly to the question, include it. If people agree with you, they'll vote it up.
Add links to your stuff from your user profile page. When people become impressed with your answers, especially in the dnd3.5 and pathfinder tagged questions, they'll check it out. I would.
List the site in your material. Then, when your users show up to ask their questions, answer them. That's the best way to make it work.
And promote the site as much as you can.
Don't create fake questions. Don't force your products into your answers.
From the FAQ:
May I promote products I am affiliated with here?
Be careful, because the community frowns on overt self-promotion and tends to vote it down and flag it as spam. Post good, relevant answers, and if they happen to be about your product, so be it. However, you must disclose your affiliation with the product in your answers. Also, if a huge percentage of your posts include a mention of your product, you're clearly here for the wrong reasons. Our advertising rates are quite reasonable; contact our ad sales team for details. We also offer free vote-based advertising for open source projects.